Abrasive roll



Y UCL 4, 1960 c. L. SHAW 2,954,650

ABRAsIvE ROLL Filed May 1e, 195s v4-1,; Av v f INVENTOR ,United statespatent O.

ABRASIVE ROLL 'Charles L. Shaw, Dayton, Ohio, assignor to LectroManufacturing, Inc., Middletown, Ohio, a corporation of Ohio Filed May16, 1958, Ser. No. 735,860

3 Claims. (Cl. 51-190) This invention relates to improvements inabrasive rolls. More particularly, this linvention concerns torming aroll lof abrasive material having a central opening `which is tor-med ina particular manner to facilitate a `rm, tenacious seating of the rollupon a drive mandrel.

` ment with lthe drive mandrel to prevent slippage or tearout and topermit `greater eiciency and eiectiveness in use of the unit by.simplifying mounting and eliminating separate handling procedures intightening the roll upon the drive mandrel or arbor.

An object of this invention is to form an abrasive roll with :a centralopening peculiarly suited to quickly and firmly seating .the roll upon ashouldered drive mandrel.

Another object of this invention is to provide a pattern shape for .an.abrasive sheet which, upon rolling, will produce a roll having acentral opening particularly suited to seat on a drive mandrel.

A further object of this invention is to provide an ,abrasive rollhaving a central opening designed to positively engage a drive mandrelwithout slippage or tear-out.

A still further object of this invention is to provide an abrasive -rollhaving a central opening shaped to iirrnly `grab a mandrel .to permithigh torque usage of the roll and consequent rapid :abrasive action.

These and other objects and advantages of this invention will beapparent .from'the following descirption and claims.

In the accompanying drawings which illustrate by way of example variousembodiments of this invention:

l Fig. l `represents a pattern for `abrasive sheets to be formed into.abrasive rolls.

Fig 2 is .a longitudinal cross sectional view of an abrasive roll;

Fig. l3 is a plan view of `an abrasive sheet prepared :for rolling;

Fig. 4 lis a perspective cross sectional view of a particular form ofabrasive roll;

Fig. 5 is a side elevation view, partly in section, showing .an abrasiveroll being mounted on a drive mandrel to form an abrading unit.

Fig. l6 is a plane view of a modiiied abrasive sheet prepared forrolling;

Fig. 7 is a longitudinal cross sectional view of an abrasive roll formedfrom the sheet shown in Fig. 6.

'Ihe sheet 1, as shown in Fig. l, has a base edge 2 and a side 4. Theportion of the sheet 1 comprising the corner Iformed by side 4 and thebase edge 2 is removed by severing the sheet along a line 3. This lineof severance is shown .as .a straight diagonal line forming an obtuseangle with the remainder of the hase edge. The

2,954,650 Patented Oct. 4, 1960 lCC manner of severance shown is thepreferred tform; however, the line 3 may also be sinuous, arcuate,serrated or of other configurations. The sheet 1 is coated with anabrasive material on one surface.

The abrasive roll 6 shown in Fig. 2 is the result of winding a sheetsuch as is shown in Fig. l into several convolutions. By commencing thewinding operation with the base edge 2, the removed portion of thesheet, .as .dened by the line 3, results in a truste-conical orsteptapered opening 7 coaxial with the abrasive roll and adjacent oneend. The tirst roll or turn of the hase edge is made of suicientdiameter to provide a cylindrical opening 8 extending from the conicalopening 7 through the cylinder. While the opening 7 is of a generalconical shape, it is to be noted `that it is actually tapered in stepscorresponding to the spiral shoulders 3a resulting when .edge 3 istoi-med into a spiral by the winding operl ation.

The .abrasive sheet 1h shown in Fig. 3 illustrates the embodiment of thecurrent invention in a sheet designed to form Ia tapered .abrasive roll.The sheet 1t) has a base edge 12 .and a `diagonal corner edge 13 andside 14 corresponding to `edges 2, 3 `and 4 respectively of the sheetshow-n in Fig. 1. `In addition, the sheet 10 has one major diagonal side15 opposed to base edge 12 resulting in one short side 16 adjacent baseedge 12. Windin-g of the sheet lll commencing with Ibase edge 12 resultsin the formation of a hollow core from that longitudinal portion ofsheet 10 corresponding to the length of side 16 and subsequent continuedwinding results in the steptapered configura-tion represented in roll 19shown in Fig. 4. The edge 15 -becomes an external helical shoulder onthe step-tapered roll y19. The edge 13 forms a tapered sea-t in roll 19as is disclosed .in Fig. 4. In the embodiment disclosed in Figs. 3 and 4the edge 13 is disposed to torm a steep pitched helical .shoulder 13awhen the sheet is wound into a roll. This shoulder may extend over lessthan `one convolution of the completed roll.

Fig. 5 illustrates yan yabr-ading tool unit compirsing a tapered roll 19and a drive mandrel 20 being assembled. T-he shadow lines 45 indicatethe nal seated position Aoit the roll 19 on the mandrel 2li. The drivemandrel 20 is provided with .a helically threaded, tapered seatingshoulder 21 joining a major `diameter shank portion 22 with the mountingarbor extension 23. As the roll 19 is mounted upon the arbor 20, theextension 23 is received -by cylindrical opening 8a permitting the rollto slide over the mandrel or arbor 20 until shoulder 21 engagesshoulders 23a of the conical opening 27. It can readily be seen thatythe mating .of such a tapered shoulder with a tapered opening provides.a large area of engagement between the driving :and driven parts andthus insures a firm and tenacious engagement.

The embodiment `of the invention shown in Fig. 6 and Fig. 7`contemplates the making and utilization of a sheet which will form .aroll having .the tapered seating portion disposed within the roll ratherthan adjacent one end. In this modification sheet 30 has a -base edge32, a rst line or edge 35 parallel .to base edge 32 and commencing at`and proceeding inwardly from `one `of the sides as side 36, .adjacent`edge 32. A second line of cut has been made to form diagonal edge 33which joins base edge 32 and the .edge resulting -irom .the line of cut35. The line of severance of edge 33 vis disposed at an obtuse anglerelative to the remaining base edge 32. It can readily be seen thatcutting along lines 33 and 35 will sever or remove la portion of onecorner of the sheet 30. Subsequent to preparation of sheet 30, it iswound into a roll, commencing with base `edge 32, to form an abrasiveroll of the general configuration of the roll 38 shown in lFig. 7. It isto be noted that `the configuration of sheet 30 results in a dispositionof the conical seating portion 37 internally of the roll rather thanadjacent one end. It is to be understood that this configuration resultsin a -roll which will seat further back on a man- V,dreland provides thearea of effective engagement. of the roll with .the mandrel nearer thegeometrical center of the roll .and consequentlyplaces the point offorce or torque application to the rollnearer to the center of tforcesresulting from the .abrasive action of the roll.

The criterion for `determining the angle oi: side 3, 13 orV 33 withrespect to the adjacent sides is that the i11- cluded angle A (see Fig.5) defined by the resulting tapered opening should be less than theincluded angle B defined by the shoulder 21 of the mandrel. Thus, foruse on many mandrels currently utilized in industry, applicant has foundthat the preferred form of his invention is :wherein Ithe edge 3, 13 or33 makes a lar-ge obtuse `angle, approaching 180 with the remaining edge2, 12 or 32. The resulting helical shoulder, as 13a, .isthen of .a steeppitch and may extend over less than one convolution of the resultingroll las. illustrated in Fig. 4. This coniiguration has the addedadvantage that the shoulder 13a is disposed at a greater angle to thethreads of shoulder 21 to facilitate firm eng-agement and easy assembly.

ln each of the above structures, it is to be noted that a considerableportion of the sheet is of full width along la substantial portion ofsides 4, 14 and 36. This configuration results in a rolled structurehaving several convolutions of material, as .at 39, 40 .and 41, backingup the entire length of .the area of the conical openings 7, 27 and 37.These convolutions serve to back up Vthe stepped convolutions .formingthe step-tapered area to prevent stretching of .the material andexpansion of the opening, thus maintaining a rm grip between thedrivemandrel shoulder and the conical shoulder of the roll.

lt can readily be seen that the above disclosed structure results in aroll having a .seating shoulder which permits quick but ltenaciousengagement between the roll .and the driving mandrel or arbor. The.greater .area of engagement and the firmer grab had by the mandrel uponthe drive roll prevents slippage of .the 4roll upon the mandrel. Also,the frequency of tear-out has been greatly reduced, .due to the mode andincreased area of jointure between the parts.

The size .and taper of the conical portion of the openling may, ofcourse, be varied to suit individual work applications .and theparticular mand-reis or arbors involved. Further, the general outline ofthe abrasive sheet .may be varied in .many shapes to effectuate nalvarious 4 by rolling an ordinary sheet of abrasive material and thenceldrilling or countersinking from one end to form a conical shoulder.Such a .countersinking results in a truer conical configuration but`does lnot provide the helical ridges or shoulders of the abovedescribed preferred internal structure.

While the invention has been described in connection with differentembodiments thereof, it will be understood that it is capable of furthermodication, and .this application is intended .to cover any variations,uses,V or adaptations of the invention fol-lowing, in general, theprinciples of the invention .and including such `departures from thepresent disclosure as come within known or customary practice in the artto which the invention pertains, and as may -be lapplied .to theessential features hereinbefore set forth and as fall within the scopeof the invention or the limits of the Iappended claims.

Having thus described my invention, what I claim is:

1.A An abrading unit comprising in combination, an abrasive r-oll and ladrive mandrel in assembled relationship, said abrasive roll formed witha coaxial opening having a substantially rusto-conical portion and acylinfdrical portion, said drive mandrel having a shank portion, .amounting yarbor of lesser diameter than said shank portion 4and atapered seating shoulder between said shank portion and said mount-ingarbor, wherein Vsaid seating shoulder engages said Iroll withsaid-frusto- .substantially frusto-conical portion engaging said seatingshoulder.

3. An abra-ding unit .as in claim 2 and wherein said substantiallyIconical portion is step-tapered in a manner v delined by ahelicallydisposed edge of .said wound sheet material' and wherein .said taperedseating shoulder is threaded.`

References Cited in the file of this patent UNITED STATES PATENTS w am.were@ e

